The present invention relates to the field of underwater photography.
Many sub-aquatic life forms possess a capability of fluorescence, which is sometimes mistaken for bioluminescence, the light radiating of fireflies. Fluorescence, in contrast, is the emission of light from a body, during illumination by excitation light having a higher frequency than the light emitted by the fluorescing body. When the excitation light is extinguished, the light produced by fluorescence ceases.
As an underwater photographer, I tried to photograph fluorescent aquatic life forms at night because they are most active at night. I was unsuccessful in doing so. The fact that the photographs needed to be exposed in darkness with very limited ambient light, and that ultra-violet (uv) light is needed to excite the fluorescence of these undersea creatures, defeated my ability to capture decent images of the undersea creatures, even with high speed film.
I began to experiment with building my own underwater camera-illumination apparatus using black light sources such as blue-black ultra-violet bulbs, which still did not produce satisfactory photographs. When I utilized the commonplace ultra-violet-black lamp, there was not enough light emitted to produce any image except the ghost image of the fluorescent pigments of the observed animals. My goal was to photograph the animals and also excite or enhance their fluorescence.
My success finally came about by employing a pair of commercially available fluorescent light bulbs that are commercially designated as xe2x80x9cU/V Whitexe2x80x9d light tubes, and that are commonly used as insect killing lights, These bulbs have a substantial, probably a maximum, ultraviolet (uv) light spectrum output component at about 365 nanometers (nm), similar to the ordinary blacklight bulb, but they also output significant amounts of white light, which produce enough ambient light for my purpose, to enable the aforesaid desired satisfactory photographs of aquatic creatures at night.